Streptococcus pyogenes
|
Morphology
|
Aerobic, gram-positive, non-motile, non-sporing cocci, extracellular bacterium. It
has a β-hemolytic growth pattern on blood agar
|
|---|---|
|
Disease
|
Group A (β-hemolytic) streptocci (GAS), streptococcal sore throat, strep throat, pharyngitis,
scarlet fever, impetigo, erysipelas, puerperal fever, necrotizing fasciitis, toxic
shock syndrome, septicaemia, acute rheumatic fever, acute post-streptococcal glomerulonephritis,
gas gangrene
|
|
Zoonosis
|
Cows infected by humans are intermediate hosts and can pass the bacterium in their
milk, which, if consumed unpasteurized, can infect other humans
|
|
Host Range
|
Humans are primary reservoir for this bacterium, although cattle can also act as a
reservoir
|
|---|---|
|
Modes of Transmission
|
Transmission via respiratory droplets, hand contact with nasal discharge and skin
contact with impetigo lesions
|
|
Signs and Symptoms
|
Respiratory and gastrointestinal illness
|
|
Infectious Dose
|
Unknown
|
|
Incubation Period
|
Generally 1-3 days
|
|
Prophylaxis
|
Administering penicillin to carriers has been shown to reduce the number of people
infected during an outbreak of streptococcal sore throat
|
|---|---|
|
Vaccines
|
None.
|
|
Treatment
|
Penicillin is used for respiratory tract infections (pharyngitis) and macrolides or
lincosamides are used if there are allergies. Clindamycin may be used in cases of
necrotizing fasciitis and surgical debridement of the affected area is necessary
|
|
Surveillance
|
Monitor for symptoms of infection.
|
|
MSU Requirements
|
Report any exposure
|
|
Laboratory Acquired Infections (LAIs)
|
78 documented cases since 1999
|
|---|---|
|
Sources
|
Respiratory specimens, skin lesions, blood, sputum and wound exudates. Cultures, frozen
stocks, other samples described in IBC protocol.
|
|
Canadian MSDS:
|
|
|---|---|
|
BMBL
|
|
|
CDC
|
|
|
NIH Guidelines
|
|
Risk Group 2
|
Agents that are associated with human disease which is rarely serious and for which preventive or therapeutic interventions are often available. |
|---|---|
|
BSL2
|
For all procedures involving suspected or known infectious specimen or cultures.
|
|
ABSL2
|
For all procedures utilizing infected animals.
|
|
Small
|
Notify others working in the lab. Remove PPE and don new PPE. Cover area of the spill
with absorbent material and add fresh 1:10 bleach:water. Allow 20 munutes (or as directed)
of contact time. After 20 minutes, cleanup and dispose of materials.
|
|---|---|
|
Large
|
|
|
Mucous membrane
|
Flush eyes, mouth, or nose for 5 minutes at eyewash station.
|
|---|---|
|
Other Exposures
|
Wash area with soap and water for 5 minutes.
|
| Reporting |
Immediately report incident to supervisor, complete a First Report of Injury form, and submit to Safety and Risk Management.
|
|
Medical Follow-up
|
During business hours: Bridger Occupational Health 3406 Laramie Drive. Weekdays 8am -6pm. Weekends 9am-5pm
After business hours: Bozeman Deaconess Hospital Emergency Room 915 Highland Blvd Bozeman, MT |
|
Disinfection
|
1% sodium hypochlorite, 4% formaldehyde, 2% glutaraldehyde, 70% ethanol, 70% propanol,
2% peracetic acid, 3-6% hydrogen peroxide and 0.16% iodine
|
|---|---|
|
Inactivation
|
Inactivated by moist heat (15 minutes at 121° C) and dry heat (1 hour at 170° C).
|
|
Survival Outside Host
|
The bacterium can survive on a dry surface for 3 days to 6.5 months. It has been found
to survive in ice cream (18 days), raw and pasteurized milk at 15-37 ºC (96 hrs),
room temperature butter (48 hrs), and neutralized butter (12-17 days). GAS has been
found to last several days in cold salads at room temperature
|
|
Minimum PPE Requirements
|
Lab coat, disposable gloves, safety glasses, closed toed shoes, long pants
|
|---|---|
|
Additional Precautions
|
Additioanl PPE may be required depending on lab specific SOPs and IBC Protocol. |